Example embodiments of inventive concepts relate to a semiconductor memory device, and more particularly, relate to a nonvolatile memory device and/or a memory system including the nonvolatile memory device.
A semiconductor memory device may be fabricated using semiconductors such as silicon (Si), germanium (Ge), gallium arsenide (GaAs), indium phosphide (InP), and the like. Semiconductor memory devices may be classified into volatile memory devices and nonvolatile memory devices.
The volatile memory devices may lose stored contents at power-off. The volatile memory devices may include a static RAM (SRAM), a dynamic RAM (DRAM), a synchronous DRAM (SDRAM), and the like. The nonvolatile memory devices may retain stored contents even at power-off. The nonvolatile memory devices may include a read only memory (ROM), a programmable ROM (PROM), an electrically programmable ROM (EPROM), an electrically erasable and programmable ROM (EEPROM), a flash memory device, a phase-change RAM (PRAM), a magnetic RAM (MRAM), a resistive RAM (RRAM), a ferroelectric RAM (FRAM), and the like. The flash memory device may be roughly divided into a NOR type and a NAND type.
A NAND flash memory device may have a two-dimensional or three-dimensional memory cell array. A three-dimensional NAND flash memory device may have a shared word line structure within a memory block.